Key Points
Perennials are best divided in the spring and fall when the weather is cooler. Spring-blooming perennials should be divided in the fall. Late-summer and fall-blooming perennials should be divided in the spring.
When your perennials are overflowing their beds, it’s time to divide them or split them into multiple smaller sections to be replanted. As a general rule, division should occur in the spring or fall when the weather is cooler to minimize stress on the plants.
But is one better than the other? We asked two gardening experts when the best time to divide perennials is, and they were eager to share their valuable insight.
Here’s everything you need to know about dividing perennials, including the best time to do it and how to do it right.
Meet the Expert
Juliet Howe is the founder of Twigs Design, a garden and floral design company based in Fairfield County, Connecticut.
Laura Janney is a garden and landscape designer and the CEO of The Inspired Garden Masterclass.
Want more gardening tips? Sign up for our free gardening newsletter for our best growing tips, troubleshooting hacks, and more!
The Best Time to Divide Perennials
Tree peony.
Credit:
Jasenka Arbanas / Getty Images
Given these pros and cons, is there a best time to divide perennials? In short, one isn’t inherently better than the other. However, certain perennials are better-suited to spring division than fall division, and vice versa.
“Spring is more ideal for late summer and fall blooming perennials, and fall for spring blooming and early summer perennials,” says Laura Janney, CEO of the Inspired Garden Masterclass. “Midsummer can be done either season.”
For example, peonies, irises, daffodils, and astilbes are best divided in the fall, while perennials like sedum, asters, coneflower, lilies, and black-eyed Susans are best divided in the spring.
But if you didn’t get around to dividing your spring-blooming plants in the fall, you can still tackle the task in the spring. The plant may not bloom as profusely during its first season, but should recover and establish for its second year. The same can be said for dividing late-summer and fall-blooming perennials in the fall.
Ultimately, it’s the growers’ choice. As Howe says, sometimes the best time to divide your perennials is whenever you have the time to do it.
Pros and Cons of Fall Division
Credit:
Mariia Zotova / Getty Images
One of the main pros of dividing your perennials in the fall is that the plants are established, so it’s easy to visualize what needs to move where, says Juliet Howe, founder of Twigs Design.
In comparison, it can be challenging to find your plants in the early spring when the garden is just starting to emerge from dormancy.
According to Howe and Janney, here are the top pros and cons of dividing your perennials in the fall.
Pros
Plants are easy to see and find
Weather is cooler
Plants are well-established, meaning less stress
Plants won’t need as much water
Fewer garden tasks in fall
Cons
Plants are bigger, requiring larger holes
Not a lot of time for plants to establish roots before winter
Enthusiasm and motivation to garden are lower in fall
You may need to move divisions again in spring
Tips for Dividing Perennials in Fall
Eager to divide your perennials in the fall? Howe suggests doing this at least six weeks before the first frost in your area, allowing roots time to establish.
She also says you should wait to divide plants until they’ve finished flowering. This allows the plant to focus all its energy on setting new roots for the following season.
Lastly, be sure to water your new transplants regularly and thoroughly—they don’t have established root systems to draw the water they need on their own.
Pros and Cons of Spring Division
Credit: Justus de Cuveland / Getty Images
Spring is also a great time to divide perennials. The garden is waking up after a good winter’s sleep, and plants are gearing up to put out new growth. Howe and Janney say these are the top pros and cons of spring division.
Pros
Plants are smaller and easier to move
There’s time for plants to establish roots before summer heat
You’re full of excitement and ready for a new growing season
Spring rainfall may save you some watering
Cons
Roots are more sensitive, meaning more chance of stress
Perennials need more water in the spring than in the fall
It’s harder to see all the plants and visualize the garden
Tips for Dividing Perennials in Spring
If you’re planning on dividing your perennials in the spring, there are a few things to keep in mind. First, always ensure you wait until the last frost in your area has passed before you divide, says Howe. An unexpected frost can be detrimental to newly transplanted perennials.
Next, staying on top of watering is vital. Perennials divided in the spring will need more watering than those split in the winter.
While spring rainfall can help, you should expect to be doing plenty of manual watering too. Keep them well-hydrated to give them the best chance of survival once the intense summer heat kicks in.
Comments are closed.